Cowl ventilator



Patented Nov. 14, 1933 UNITED STATES- COWL VENTILATOR Barry L.McPherson, Hollywood, Tenn.

Application December 29, 1927' Serial No. 243,234

so Claims. (o1. 244-31) This invention relates to improvements in cowlventilators for airplanes or the like, and has especial relation tomeans for regulating or controlling the air delivered for purposes ofcooling the cylinders of an air cooled motor and for reducing theresistance of such parts incident to their rapid passage through theair.

In designing airplanes, which necessarily move through the air at highvelocities, every effort is made to stream line the parts so thatminimum resistance may be offered to passage of the planes through theair. With the advent of air cooled motors, the cylinders have beenallowed to protrude through the cowl inorder to effect the necessarycooling, and the resistance set up by these cylinders has materiallyadded to the resistance of the plane and has to a considerable extentdisturbed the stream line and-added a resistance out of all proportionto the apparent obstruction.

With these facts in view, the objects of this invention are:

(a) To establish a stream line cowl for an air cooled motor; a

(b) To separate the cylinder cooling air from the remaining air passingthe plane, toeifect the cooling of the cylinders with such separatedair, to reconcentrate such air into a smooth flowing stream, and todeliver same into the exterior air stream in a direction effective todecrease resistance;

(0) To regulate the amount of cooling air diverted past the cylinders tobe cooled;

-(d) To reduce the air velocity adjacent the cylinders;

(e) To provide ready access to the cylinders for repairs, or adjustment;

(f) To restore the air velocity as the diverted air is restored to theprimary stream; and

(9) To generally improve the design and construction of such structures.

The means by which the foregoing and other objects are accomplished andthe manner of their accomplishment will readily be understood from thefollowing specification on reference to the accompanying drawings inwhich:

Fig. 1 is a side elevation of the front portion of an airplane showing apart ofthe cowl in section.

Fig. 2 is a sectional elevation on a larger scale taken on the line11-11 of Fig. 1 showing one form of regulating mechanism.

Fig. 3 is a sectional detail on a more enlarged scale taken on the lineII [III of Fig. 2 showing instance 1'1, 18, (Fig. 3).

REl-SSUED a means for securing the cowl plates to the adjustingmechanism.

Fig. =4 is a similarly enlarged detail showing a locking washer on theouter surface of the cowl.

Referring now'to the drawings in which the parts are designated bynumerals;

10 is an inner cowl through which the cylinders 11 project. 12 is thenose of the plane and 13 the propeller blades.

Surrounding the cylinders, and enclosing them circumferentially, is asectional cowl made up of a number of sections, 14, 15, 16, 17 etc.,preferably one for each of the engine cylinders.

At the rear, each of the sections is supported by posts 23, whichproject outward from the inner cowl 10, and to which posts they arehinged, each post supporting the adjacent edges of two sections, so thateach section has its two edges supported and hinged at the rear end.

At the forward end the sections overlap, section 15 for examplepreferably overlying the adjacent sections 14 and 16, sections 17,overlying 16 and 18. These forward ends are movable in-- ward oroutward, that is toward or away from the inner cowl '10, so that theannular space there- 50 between may be decreased or enlarged. Toaccomplish this, thrust members 24 are extended outward through theinner cowl 10, near the forward end of these sections and passed throughslots 25, 26 in the overlapped sections, as for 5 Integral with themembers 24 are inner collars 27 which are of greater size than the slots25, 26 and outer heads 28- of less size than these slots.

29 are slotted washers which may be disposed between the heads 28 andthe outer surfaces of the overlapping sections to secure them to themembers 24 firmly but not sufliciently tight to prevent their slidingthe one on the other when adjustment is made. By removing these washersthe sections may be disconnected from the thrust members andthereafterbe turned back to give access to the engine cylinders.

Within'the cowl 10, these rods are connected to bell crank levers 30, to38 inclusive which are pivoted in brackets 39 and 40, secured to theinner surface of the cowl. Bell cranklever 30 and 31; 31 and 32; 32 and33; 33 and 34; 35 and- 36; 3 6 and 3'7 3'1 and 38; are connectedtogether in pairs by connecting rods 41, and bell crank levers 34 and35, by a threaded connecting'rod 42, the ends of the rods being pivotalattached to their correspondinglevers. No onnection need be establishedbetween levers 38 and '40.

44 is a sprocket wheel which has an integral, 4

interiorly threaded hub 45, which is disposed on the correspondinglythreaded rod 42.

The wheel 44 may be turned on the rod 42 and isheld against lateralmovement by a double bracket 46, having bracing arms 47, whoseextremities are preferably disposed between the brackets 40 and the cowl10, and secured to the cowl by the fastenings that are used to securethese brackets.

48 is a sprocket chain disposed over the sprocket wheel 44 and extendingtherefrom to a control sprocket wheel 49 on the instrument board 50 ofthe plane. When therefore the wheel 49 on the instrument board isrotated the threaded hub of the wheel 44 shifts the rod 42 to the leftor right as the case may be. If to the left (Fig. 2) all the bell cranklevers will be correspondingly shifted and the thrust members 24 movedoutward concurrently thus moving the forward ends of the sections 14, 15etc. outward and enlarging the annular space around the inner cowl, andincreasing the amount of air diverted past the cylinders.

If the rod 42 is shifted to the right the sections are drawn inward,decreasing the annular space, and correspondingly the amount of airallowed to pass the cylinders.

It will be especially noted that the sectional cowl is shaped to conformto the general stream line of the nose, and of the body of the planebehind the sectional cowl. It will further be noted that the annularspace between the sectional cowl and the inner cowl increases from frontto rear, at least as far as the cylinders, so that air diverted to thecylinders will pass into an enlarging space and be allowed to slow downin velocity while passing the cylinders, thus reducing the resistanceset up by the cylinders to such air passage. After passing the cylindersthe air is diverted outward by the inner cowl and into the air streampassing over the outer or sectional cowl.

It will further be noted that all exposed parts such as the thrust rods24, the collar 2'7 and the heads 28 and even the forward ends of thewashers 29 are stream lined so far as possible to reduce air resistance,the posts 23 being also so stream lined.

In use the operation of the device may be controlled from the instrumentboard, by turning the hand wheel 49. This motion is transmitted throughthe chain 48 to the wheel 44 and the opening or closing of the front ofthe sectional cowl thereby effected.

33y the use of such a device the head resistance may be cut down' andincreased mileage and speed result. At the same time the motortemperatures may be controlled and increased efficiencies be therebyobtained.

It will be distinctly understood that the drawings are introduced forthe purpose of illustration only and particularly that the means wherebythe opening and closing of the sectional cowl is effected is typicalonly.

It is therefore to be distinctly understood that I do not wish to belimited to the detail herein shown and described, except where suchlimitation is specifically set out in the claims.

It will further be understood that the term nose while inclusive of theterm spinner is not limited to such term; and it will further beunderstood that in the appended claims, I specifically disclaim anystructure in which the inner cowl is not a part additional to the cra kC2 6 0f the engine.

Having described the invention. what I claim is:

1. A power plant, comprising a cowl, a plurality of cylinders projectingtherethrough, and an auxiliary cowl surrounding said cylinders, saidauxiliary cowl comprising alternate over-lapping and underlyingsections, each disposed over a cylinder, means for supporting the rearends of said sections and joint means for adjustably supporting theforward ends of the lapped edges of each two sections.

2. A power plant, comprising a cowl, a plurality of cylinders projectingtherethrough, and an auxiliary cowl surrounding said cylinders, saidauxiliary cowl comprising alternate over-lapping and underlying section,each disposed over a cylinder, means for hingedly supporting the rearends of said sections, and releasable means for supporting the forwardends of the lapped edges of each two sections.

3. In an air cooled engine assembly, an inner cowl, a sectional outercowl comprising a plurality of lapping sections, means for supportingthe rear ends of said sections, and means for adjusting the front endsthereof.

4. A power plant comprising an inner cowl, a plurality of cylindersprojecting therethrough, and an auxiliary cowl surrounding said innercowl and cylinders, auxiliary cowl comprising alternate, over-lappingand underlying sections, each disposed over a cylinder.

5. A power plant comprising an inner cowl, a plurality of cylindersprojecting therethrough, an auxiliary cowl surrounding said inner cowland cylinders, said auxiliary cowl comprising alternate over-lapping andunderlying sections, each disposed over a cylinder, means for supportingthe rear ends of said sections, and joint means supporting the forwardend of the lapped edges of each two sections.

6. A power plant comprising an inner cowl, a plurality of cylindersprojecting therethrough, an auxiliary cowl surrounding said inner cowland cylinders, the front end of said auxiliary cowl being spaced fromsaid inner cowl and the area between said cowls increasingrearwardlymeans for supporting the rear end of said auxiliary cowl, and means foradjusting the spacing of the front end of said auxiliary cowl from saidinner cowl.

I. In an air cooled engine, an annular inner cowl, a plurality ofcylinders projecting outward through said cowl. an annular sectionalcowl surrounding, and spaced away from, said inner cowl and cylinders.the distance between said cowls diverging rearwardly, and means forvarying the distance of the front of said sectional cowl from said innercowl.

8. In an air cooled engine, an annular inner cowl, a plurality ofcylinders projecting outward through said cowl, an annular sectionalcowl comprising a plurality of lapping sections, surrounding, and spacedaway from, said inner cowl and cylinders, means for supporting the rearends of said cowl sections, and means for varying the distance of thefront ends of said cowl sections from said inner cowl.

9. In an air cooled engine, an annular inn r cowl, a plurality ofcylinders projecting outward Lil through said cowl, an annular sectionalcowl surrounding, and spaced away from, said inner cowl and cylinders,the area between said cowls diverging rearwardly, posts extendingoutward from said inner cowl, pivotal means connecting said sectionalcowl to said posts, and means for I 1,934,94 4 varying the distance ofthe front of said sectional cowl from said inner cowl.

10. In an air cooled engine, an inner-cowl, an outer cowl comprising aplurality of sections, posts projecting from said inner cowl, pivotalmeans securing the rear end of said sections to said posts, rodsprojecting from within said .inner cowl and secured to the forward endof sections, bell crank levers Within saidinner cowl each secured to oneof said rods, linkage connecting said bell crank levers, and means forshifting said links to shift said rods inward and outward.

11. In an air cooled engine, an inner cowl, an annular outer cowlcomprising a plurality of sections, posts projecting from said innercowl, pivotal means securing the rear end of said sections to saidposts, rods projecting from within said inner cowl and secured to theforward end of said sections, bell crank levers withinsaid inner cowleach secured to one of said rods, linkage connecting said bell cranklevers, and means for shifting said links to shift said rods inward andoutward.

12. In an air cooled engine, an annular inner cowl, an annular outercowl surrounding said inner cowl and diverging rearwardly, said outercowl comprising a plurality of sections, posts projecting from saidinner cowl, pivotal means securing the rear end of'said' sections tosaid posts, rods projecting from within said inner cowl and secured tothe forward end of said sections, bell crank levers within saidinnercowl each secured to one of said rods, linkage connecting said bellcrank levers, and means for shifting said links to shift said rodsinward and outward.

13. In a power plant, walls spaced apart and defining a passageway openat its ends, and increasing rearwardly in area, means for regulating theforward end opening, and a cylinder within said passageway.

14. In an air cooled engine assembly, an inner cowl, a sectional outercowl comprising a plurality of lapping sections, means for supportingthe rear ends of said sections, and means for adjusting the front endsof said sections, including rods, each supporting the lapped edgesof twosections. V

15. A power plant, comprising an inner cowl, a plurality of enginecylinders projecting therethrough, an auxiliary cowl surrounding saidinner cowl and cylinders, said auxiliary cowl comprising sections, eachdisposed over a cylinder, means for supporting the rear ends of saidsections, andmeans for supporting the forward ends thereof.

16. In an aeroplane, an annular cowl, a plurality of engine cylindersprojecting radially therebeyond, and an auxiliary annular cowlsurrounding said inner cowl and projecting cylinders,

said auxiliary cowl comprising a plurality of sections, each overlying acylinder, and means for securing the front and rear ends of saidsections. 17. A power plant, comprising an inner cowl, a plurality ofengine cylinders projecting therethrough, an auxiliary cowl surroundingsaid inner cowl and cylinders, said auxiliary cowl comprising sections,each disposed over a cylinder, means for hingedly supporting the rearends' of said sections, and means for releasably supporting the forwardends thereof.

18. In an aeroplane, an annular cowl, a plurality of engine cylindersprojecting radially,

therebeyond, and an auxiliary annular cowl surrounding said inner cowland projecting cylinders, said auxiliary cowl comprising a plurality ofsections, each overlying a cylinder, and means for releasably securingthe front, and hingedly securing the rear ends of said sections.

19. A power plant, comprising an inner cowl, a

plurality of engine cylinders projecting therethrough, an auxiliary cowlsurrounding said in ner cowl and cylinders, said auxiliary cowlcomprising sections, each disposed over a cylinder, means for supportingthe rear ends of said sections, and means for adjustably supporting theforward ends thereof.

20. In an aeroplane having a plurality of engine cylinders radiallydisposed, an annular cowl surrounding said cylinders, said cowlcomprising sections, each overlying a cylinder, and means for securingthe rear "ends of said sections, and means for adjustably securing theforward ends thereof.

21. In an aeroplane having a plurality of engine cylinders radiallydisposed, a cowl surrounding said cylinders, said cowl comprisingsections, each disposed over a cylinder, means for "hinging the rearends of said sections, and means for releasably securing the forwardends thereof.

\ 22. In an aeroplane havinga plurality of engine cylinders radiallydisposed, anannular cowl surrounding said cylinders, said cowlcomprising sections, each overlying a cylinder, and means for securingthe front and rear ends of said sections.

23. In an airplane, having radial engine cylinders, a nose, a cowlforming a continuation thereof, extending rearwardly therefrom to saidcylinders and thence outwardly and rearwardly, to a stream line junctionwith the fuselage of said plane, said cylinders projecting through saidcowl; and an auxiliary cowl surrounding saidcylinders and annularlyspaced at its front an rear ends from said inner cowl.

24. In an airplane, having radial engine cylinders, a nose, an innercowl forming a continuation plane, until said cylinders are reached, andthence enlarging rearwardly to such stream line continuation of saidnose, said cylinders projecting outward through said cowl,and an outercowl surrounding said cylinders and lying intermediate said nose andenlarged portion of said inner cowl, said outer cowl lying substantiallyparallel to the stream lines adjoining said nose and said enlargedportion of said inner cowl.

25. In an airplane, having radial engine cylinders, a nose, an innercowl forming a. continuation thereof, diverging rearwardly from a streamline continuation of said nose and toward parallelism with thelongitudinal axis of said plane until said cylinders are reached, andthence enlarging rearwardly to a stream line continuation of said .nose,said cylinders projecting outward through said cowl; and an outer cowlsurrounding said cylinders and lying ,intermediate'said nose andenlarged portion of said inner cowl, said outer cowl lying substantiallyparallel to the stream lines joining said nose and said enlarged portionof said inner cowl, said outer cowl being annularly spaced at both endsfrom said inner cowl.

26. Cooling means for an engine, including an inner cowl enclosingsaidengine and an outer cowl open at both ends surrounding and spaced fromsaid inner cowl to provide a passageway for cooling air therebetween,the space between said cowls being greater intermediate the ends of saidoutercowl than at one end thereof, the cylinders of said engineprojecting outward through said inner cowl into the enlarged part ofsaid air passageway.

27. In an airplane powered by an engine having cylinders with coolingfins thereon; cooling means including a nose, an inner cowl, around saidengine, forming a rearward continuation of said nose, and an outer cowlopen at both ends, surrounding and spaced from said inner cowl toprovide a passageway for cooling air therebetween, the cylinders of saidengine projecting outward through said inner cowl into the airpassageway between said cowls, whereby air may be smoothly diverted pastsaid cylinders to cool them.

28. In an airplane, an engine having radial cylinders, an inner cowlingenclosing the engine including a portion only of the cylinders with theremainder portion thereof projecting beyond the cowl and an auxiliaryouter cowling open at both ends and exteriorly stream lined, surroundingand spaced from said inner cowling.

29. In an airplane, an engine having radial cylinders, an inner cowlingenclosing the engine including a portion only of the cylinders, with theremainder portion thereof projecting beyond said cowl and an auxiliaryouter cowling belt open at both ends surrounding and spaced from saidinner cowling, said inner cowling enlarging rearwardly to a stream linejunction with the fuselage of said plane.

30. In an airplane, a cowled engine structure having the engine cylindersupported by said structure and projecting through and beyond thecowling into the surrounding air stream for cooling and an auxiliaryouter cowling open at both ends surrounding and spaced from saidstructure to separate the cooling air from the general air flow aroundthe body of the plane.

HARRY L. MCPI-IERSON.

